Acute stress enhances sensitivity to a highly attractive food reward without affecting judgement bias in laying hens

“…A second type of judgement bias task, the active choice task, was developed to address Lea, Ferguson, & Lee, 2015). Evidence for an effect of emotion manipulation on judgement bias was reported in all studies except Hernandez et al (2015).…”

Section: Active Choice Task With Positive Reinforcement (+ +)mentioning

confidence: 99%

A “How-To” Guide for Designing Judgment Bias Studies to Assess Captive Animal Welfare

Bethell

2015

Journal of Applied Animal Welfare Science

114

130

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“…This results in an adaptive enhanced expectation of negative outcomes under ambiguity leading to risk-averse, or pessimistic, decisions. At the same time, however, there are data suggesting that mild negative mood states may be associated with an increase in reward valuation [40–44], perhaps because acquiring available rewards can help to enhance mood state; a form of mood repair [43, 45]. Longer-term and deeper negative moods may, on the other hand, be associated with devaluation of reward as evidenced by anhedonic responses [46], perhaps functioning to minimise activity and associated risks and energy expenditure [47].…”

Section: Discussionmentioning

confidence: 99%

Cognitive Bias in Ambiguity Judgements: Using Computational Models to Dissect the Effects of Mild Mood Manipulation in Humans

et al. 2016

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Positive and negative moods can be treated as prior expectations over future delivery of rewards and punishments. This provides an inferential foundation for the cognitive (judgement) bias task, now widely-used for assessing affective states in non-human animals. In the task, information about affect is extracted from the optimistic or pessimistic manner in which participants resolve ambiguities in sensory input. Here, we report a novel variant of the task aimed at dissecting the effects of affect manipulations on perceptual and value computations for decision-making under ambiguity in humans. Participants were instructed to judge which way a Gabor patch (250ms presentation) was leaning. If the stimulus leant one way (e.g. left), pressing the REWard key yielded a monetary WIN whilst pressing the SAFE key failed to acquire the WIN. If it leant the other way (e.g. right), pressing the SAFE key avoided a LOSS whilst pressing the REWard key incurred the LOSS. The size (0–100 UK pence) of the offered WIN and threatened LOSS, and the ambiguity of the stimulus (vertical being completely ambiguous) were varied on a trial-by-trial basis, allowing us to investigate how decisions were affected by differing combinations of these factors. Half the subjects performed the task in a ‘Pleasantly’ decorated room and were given a gift (bag of sweets) prior to starting, whilst the other half were in a bare ‘Unpleasant’ room and were not given anything. Although these treatments had little effect on self-reported mood, they did lead to differences in decision-making. All subjects were risk averse under ambiguity, consistent with the notion of loss aversion. Analysis using a Bayesian decision model indicated that Unpleasant Room subjects were (‘pessimistically’) biased towards choosing the SAFE key under ambiguity, but also weighed WINS more heavily than LOSSes compared to Pleasant Room subjects. These apparently contradictory findings may be explained by the influence of affect on different processes underlying decision-making, and the task presented here offers opportunities for further dissecting such processes.

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“…On the other hand, some adverse conditions have also been found to increase the sensitivity to reward (Van den Berg et al 1999). For example, acute stress caused by isolation increased the motivation for food in hens (Hernandez et al 2015), and chronic mild stress in rats and music inducing a depressed mood in humans increased the motivation for highly positive sweet food rewards, albeit the latter can also be interpreted as a measure of craving rather than response to the reward (Willner et al 1998). The relationship between mood and reward sensitivity is thus not that straightforward.…”

Section: Motivation To Run For the Rewardmentioning

confidence: 99%

Effects of early life and current housing on sensitivity to reward loss in a successive negative contrast test in pigs

et al. 2019

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Animals in a negative affective state seem to be more sensitive to reward loss, i.e. an unexpected decrease in reward size. The aim of this study was to investigate whether early-life and current enriched vs. barren housing conditions affect the sensitivity to reward loss in pigs using a successive negative contrast test. Pigs (n = 64 from 32 pens) were housed in barren or enriched conditions from birth onwards, and at 7 weeks of age experienced either a switch in housing conditions (from barren to enriched or vice versa) or not. Allotting pigs to the different treatments was balanced for coping style (proactive vs. reactive). One pig per pen was trained to run for a large reward and one for a small reward. Reward loss was introduced for pigs receiving the large reward after 11 days (reward downshift), i.e. from then onwards, they received the small reward. Pigs housed in barren conditions throughout life generally had a lower probability and higher latency to get the reward than other pigs. Proactive pigs ran overall slower than reactive pigs. After the reward downshift, all pigs ran slower. Nevertheless, reward downshift increased the latency and reduced the probability to get to the reward, but only in pigs exposed to barren conditions in early life, which thus were more sensitive to reward loss than pigs from enriched early life housing. In conclusion, barren housed pigs seemed overall less motivated for the reward, and early life housing conditions had long-term effects on the sensitivity to reward loss.

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Acute stress enhances sensitivity to a highly attractive food reward without affecting judgement bias in laying hens

Cited by 39 publications

References 35 publications

A “How-To” Guide for Designing Judgment Bias Studies to Assess Captive Animal Welfare

A “How-To” Guide for Designing Judgment Bias Studies to Assess Captive Animal Welfare

Cognitive Bias in Ambiguity Judgements: Using Computational Models to Dissect the Effects of Mild Mood Manipulation in Humans

Effects of early life and current housing on sensitivity to reward loss in a successive negative contrast test in pigs

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